Shift In Response Criterion Research Articles

Partial matching in the Moses illusion: response bias not sensitivity.

Previous research has demonstrated that people have enormous difficulty in detecting distortions in such questions as, "How many animals of each kind did Moses take in the Ark?" Reder and Kusbit (1991) argued that the locus of the effect must be the existence of a partial-match process. Other research has suggested that this partial-match process operates at the word level and that, with adequate focus on the relevant word, the Moses illusion is greatly diminished. The present experimental results argue that those conclusions were based on a shift in response criterion with no concomitant change in ability to detect distortions. Furthermore, the data suggest that the matching process operates below the word level, at the level of distinctive features.

Expectancy for Change and Adaptation to a New Signal Probability

An experiment showed that the higher the 18 observers' expectancy for change in signal probability (without knowing the future probability), the more successful the adaptation to a new probabilistic environment in terms of shift in response criterion.

Theoretical note on a practical problem: Effective screening of drinking water for taints

Threshold models indicate that the best way to improve the effectiveness of sensory screening of water at the point of production is to give assessors sensory training, but we argue that it is likely to be ineffective. The notion of sensory threshold has been displaced in psychophysics by signal-detection models which assume that the assessor is uncertain on every trial, but makes an unconscious decision about the presence or absence of the attribute. The decision can be influenced by many factors other than the strength of the attribute and the sensitivity of the assessor Taking account of possible changes in response criterion as well as in sensory sensitivity indicates a quite different way of improving sensory screening by attempting to counteract vigilance decrement and the effects of relative judgement. This approach indicates that, rather than trying to increase the sensitivity of assessors, we should aim to prevent shifts in response criterion and the transmission of errors from one sample to the next. A method that has proved successful with industrial inspection and military watchkeeping is to add artificial ‘signals’ to those being assessed and give the assessors immediate feedback on their success in judging them.

Detection of unexpected signals: Effect of shifts in response criteria

The percentage of trials in which listeners were able to detect (in a single-interval, forced-choice task) a faint expected signal compared to an unexpected signal was determined when the signal was a click presented in a noise background. The signal was positioned 0.5 s from the beginning of a 1.5-s observation interval in 80% of the signal trials and elsewhere in the interval in the remainder. Detection of the unexpected signal was best when it occurred close to the expected temporal position. An analysis of the false alarms following each type of trial—expected signal, unexpected signal, and noise only—showed no differences. It is argued that differences would have been anticipated if degradation of performance for remotely positioned, unexpected signals had been a result of changes in the listener's response criterion. Alternatively, these findings are interpreted to indicate that performance was related to attentional factors that influenced detection directly, perhaps through a temporal window analogous to a critical band in the frequency domain.